Operators

example	name	result
$a + $b	Addition	Sum of $a and $b.
$a - $b	Subtraction	Remainder of $b subtracted from $a.
$a * $b	Multiplication	Product of $a and $b.
$a / $b	Division	Dividend of $a and $b.
$a % $b	Modulus	Remainder of $a divided by $b.

There is only one string operator: the concatenation operator (".").

$a = "Hello ";
$b = $a . "World!"; // now $b = "Hello World!"

However, there are certain basic string functions:

substr

trim

strlen

, etc.

example	name	result
$a and $b	And	True of both $a and $b are true.
$a or $b	Or	True if either $a or $b is true.
$a xor $b	Or	True if either $a or $b is true, but not both.
! $a	Not	True if $a is not true.
$a && $b	And	True of both $a and $b are true.
$a \|\| $b	Or	True if either $a or $b is true.

example	name	result
$a == $b	Equal	True if $a is equal to $b.
$a != $b	Not equal	True if $a is not equal to $b.
$a < $b	Less than	True if $a is strictly less than $b.
$a > $b	Greater than	True if $a is strictly greater than $b.
$a <= $b	Less than or equal to	True if $a is less than or equal to $b.
$a >= $b	Greater than or equal to	True if $a is greater than or equal to $b.